Step ladder supported portable bridge-crane structure for lifting materials to the top of an adjacent building

ABSTRACT

A portable bridge-crane structure designed to provide means of lifting construction materials and equipment such as compressors for air conditioners to the roof of a building where construction or installation is to be performed. Said portable bridge-crane structure being supported at a distance above ground between a step ladder and the wall and the roof of a building where construction or installation is to be done.

United States Patent Cox [ 1 Sept.2, 1975 STEP LADDER SUPPORTED PORTABLE BRIDGE-CRANE STRUCTURE FOR LIFTING MATERIALS TO THE TOP OF AN ADJACENT BUILDING [76] Inventor: Doyle W. Cox, 402 l/2 N. Walnut St., Lampasas, Tex. 76530 [22] Filed: July 16, 1974 [21] Appl. No.: 488,944

[52] US. Cl. 254/142; 182/102; 187/10 [51] Int. Cl. E06c 7/16 [58] Field of Search 254/142, 143, 139.1;

187/9 R, 9 E, 10 R; 182/625, 102, 172, 171, 228, 173; 248/238, 210; 214/95 R [56] References Cited UNITED STATES PATENTS 662,566 11/1900 Jones 248/238 731,708 6/1903 Quinn 182/102 799,782 9/1905 Ellinger 248/238 2,212,384 8/1940 Brande]; 182/228 Primary ExaminerRobert J. Spar Assistant Examiner-Kennetlh Noland [5 7] ABSTRACT A portable bridge-crane structure designed to provide means of lifting construction. materials and equipment such as compressors for air conditioners to the roof of a building where construction or installation is to be performed. Said portable bridge-crane structure being supported at a distance above ground between a step ladder and the wall and the roof of a building where construction or installation is to be done.

16 Claims, 5 Drawing Figures PATENTE SEP '2 I975 sum 2 n5 2 STEP LADDER SUPPORTED PORTABLE BRIDGECRANE STRUCTURE FOR LIFTING MATERIALS TO THE TOP OF AN ADJACENT BUILDING SUBJECT MATTER OF THE INVENTION This invention relates generally to cranes and load lifting apparatus and relates more specifically to portable and manually operated load lifting structures and apparatus that can be erected on the work site by a single operator.

OBJECTS OF THE INVENTION A major object of the invention is to provide a simple portable manually operated means of lifting building materials, equipment and heavy loads to the roof tops of small buildings where construction or equipment installation work is to be done.

Another object of the invention is to devise a load lifting crane structure of such proportions, weight and design as to permit a single workman to load the device into a pick-up truck for transportion and for said single workman to be able to erect said load lifting crane by his own efforts alone at the work site.

A further object of the invention is to provide a portable, quickly and easily erected and operated hoist means of lifting compact but heavy air compressors for air conditioning systems to the rooftops of buildings where such equipment is to be installed.

A further related object of this invention is to provide a swivelable or rotatable hoist support means that is so positioned that the air compressor or other load can be lifted straight up from the ground without dragging it against the building or other adjacent structures with means of rotating the suspended load to a position over the roof surface of the building where it can be lowered with minimum struggle and inconvenience. This is to be accomplished in part by arranging the hoist means in a selected position where the load will be lifted through a planned opening in the center of the bridgecrane hoist structure.

Still another object of the invention is to provide inexpensive, convenient and readily available vertical support means for said bridge-crane load lifting structure upon which work is to be performed for one of the vertical support means and using an ordinary step ladder as the second vertical support means.

Still a further object of the invention is to provide adjustable standoff abutment strut means to control the distance and space between a vertical ladder support and the wall of the building where the device is to be used and to provide lateral bracing support for the entire bridge-crane structure while a load is being lifted to the roof top.

Still another object of the invention is to provide, in association with said step-ladder supported bridgecrane structure, a hinged folding step platform that can be manually manipulated by means of a simple rope pull, and to so devise said foldable step platform so that it hangs folded in an out-of-the-way position while load lifting work is being performed and that can be quickly and easily unfolded and lifted into position when a workman needs to have a convenient and safe way to step across the space between the top of the ladder and the roof-top of the building where work is being performed.

A further object of an alternate version of the invention will be to devise a bridge-crane crown structure only with socket mating provisions on the outside legs of the bridge-crane structure to make the ladder support attachable-detachable such that the bridge-crane crown structure can be used in association with any available step ladder.

Other objects and advantages of this invention will become apparent through consideration of the following description and appended claims in conjunction with the attached drawings in which:

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a perspective view of one version of the portable step ladder supported bridge-crane structure showing the vertically positioned step ladder as a unitary part of the bridge-crane structure with the folding step platform in the vertical out-of-the-way position.

FIG. 2 is a partial perspective detail view of the unitary step ladder and bridge-crane structure version of the device showing the modified swivelable, slidable, and telescopic spaced apart stand-off wall abutment struts provided with lateral slip-resistant feet.

FIG. 3 is a partial perspective view of the unitary step ladder and bridge-crane structure version of the device showing how an operator would pull the folding step platform upward to its horizontal in-use position by means of the step draw line.

FIG. 4 is a perspective view of another version of the portable step ladder supported bridge-crane structure showing an attachable-removable step ladder as one of the vertical support means and how the bridge-crane structure is used by an operator to hoist materials and equipment through the load lift passageway by means of the swivel pulley hoist.

FIG. 5 is a detailed partial perspective view of the bridge-crane structure version shown in FIG. 4 showing how the pulley hoist may swivel over the roof of the building being serviced to unload materials or machinery.

In describing one selected form or preferred embodiment of this Invention as shown in the drawings and described in this specification, specific terms and components are used for clarity. However, it is not intended to limit the claimed Invention to the specific form, components or construction shown and it is to be understood that the specific terms used in this illustration of the Invention are intended to include all technical equivalents which operate in a similar manner to ac complish a similar purpose.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF INVENTION Referring to the specific embodiment of the Invention selected for illustration in the accompanying draw ings, the number 11 refers to the overall combination step-ladder supported bridge-crane structure as illustrated in FIG. 1 of the drawings, herein, while the pair of spaced apart generally broad inverted U-shaped bridge-crane members at the cap or crown of the structure are designated as 12 and 13, respectively with most of said structure being formed from a strong tubular material such as metal tubing. The second or inside ends 14 and 15 of bridge-crane members 12 and 13 turn down at a slight obtuse angle to provide support legs for the inside end of said bridge-crane structure with said second or inside end of said bridge-crane structure being designed to engage and rest upon the roof of a building where construction or installation work is to be done.

At the first or outside ends of said bridge-crane members 12 and 13 the tubular members turn downward at a very slightly obtuse angle forming outside legs 16 and 17 for said bridge-crane structure 11 with said nearly vertical end legs 16 and 17 of said bridge-crane members being extended to form a vertically positioned step ladder 18 having left and right upright side rails 19 and 20 and a plurality of spaced apart step rungs 21-21 mounted transversely between the upright side rails; with said bridge-crane structures 12 and 13 and step ladder vertical support structure 18 forming a combination unitary structure 11.

The top center horizontal portions 22 and 23 of inverted U-shaped bridge-crane members 12 and 13 are made longer than the inside vertical legs of said bridgecrane members and they form and provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support step ladder 18 to the roof of the building upon which construction or installation work is being performed. In addition, at some intermediate position along the horizontal part of one of said bridge-crane members 22 and 23 is provided with a suitable mounting support structure 24 for mounting a manually operated pulley-hoist means.

Although much of the rigidity required to secure the left and right bridge-crane members 12 and 13 in parallel spaced apart relationship will be supplied by transverse ladder step rungs 21-21 between upright side rail supports 19-20, additional strength and rigidness may be imparted to the upper cap or crown portion of said bridge-crane members by providing at least one cross brace means 25 extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a secure parallel spaced apart relationship.

Since an object of the invention is to employ the roof of a building and a vertically positioned step ladder 18 to support at a position above ground a bridge-crane framework with associated block and tackle equipment swivelably supported above the central opening in said bridge-crane framework to, in effect, create a simple elevator lift shaft space between upright step ladder 18 and the side of the building 26 being serviced or worked on, the invention employs a pair of horizontally positioned spaced apart stand-off wall abutment struts 27 and 28 to maintain the vertical support step ladder at a predetermined and controlled distance from the wall 26 of the building being serviced. Each of said stand-off wall abutment struts 27 and 28 should have a length of approximately 55 to 80% of the length of the horizontal portion of each of said bridge-crane members 22-23 such that, when in use, the stand-off wall abutment struts rest against the wall of said building 26 when the inside legs 14 and 15 of bridge-crane members 12 and 13 are at rest on the roof of the building on which work is to be performed. The spaced apart stand-off wall abutment struts 27 and 28 are mounted on the turned down outside vertical leg portions 16 and 17 of the inverted U-shaped bridge-crane members 12 and 13 at an intermediate position approximately two to three feet below the top center horizontal portions 22 and 23 of the inverted U-shaped bridge-crane members l2 and 13. The stand-off wall abutment struts 27 and 28 are also approximately at a right angle to the outside vertical leg portions 16 and 17 while being parallel to the said top center horizontal portions 22 and 23 of the inverted U-shaped members 12 and 13, such that the space that is enclosed between the wall abutment struts 27 and 28, the transverse cross brace means 25 and the building wall 26 upon which work is to be performed constitutes a load passageway 29 through which materials and equipment may be lifted by the lone workman in moving such materials to the roof of the building being serviced. Load passageway 29 has a generally rectangular shape as pictured in the embodiment chosen for illustration in FIG. 4 to facilitate the lifting of large, squarish air conditioning equipment, but the step ladder supported bridge-crane structure 1 1 may have its various parts designed so that the load passageway 29 could assume a specialized shape, such as long and narrow for the transport of large, flat, thin pieces of plywood to the roof of a building.

The swivel mount support means 24 is attached in a perpendicular position to one of the inverted U-shaped bridge-crane members 12 or 13 at an intermediate point near the center of the top center horizontal portion 22 or 23 in such a position that an inverted L- shaped load hoist boom arm 30 rotatably mounted in the swivel mount support means 24 may swivel and rotate from over the load lift passageway space 29 to over the roof of the building being serviced. Suspended from the load hoist boom arm 30 is a conventional block and tackle apparatus 31 adapted to lift materials and equipment to the top of the building being serviced by means of a crown block 32, a traveling block 33 and an appropriate length of load line 34 threaded through the crown block 32 and traveling block 33 to form a conventional block and tackle to provide a means by which the lone worker on the ground may lift and rotate materials and equipment from the ground through load passageway space 29 and onto a building rooftop.

A number of different varieties of embodiments of the portable combination step-ladder and bridge-crane structure 1 1 have been combined and illustrated in one manifestation in FIG. 2 of the Drawings. One variation of the Invention includes a rotatable, slidable and adjustable mounting of the horizontally positioned spaced apart stand-off wall abutment struts 27 and 28 at an intermediate point on the outside vertical leg portions 16 and 17 of the inverted U-shaped bridge-crane members 12 and 13 by provision of rotatably and slidably adjustable mounting sleeves 35-35. These slidably adjustable mounting sleeves 35-35 are loosely but closely fitted around the outside vertical tubular leg portions 16 and 17 of inverted U-shaped bridge-crane members 12 and 13 and are provided with manually adjusted friction lock means 36-36 which are adapted to secure the setting of said slidable-adjustable sleeves 35-35 so that each of the attached stand-off wall abutment struts 27 and 28 may be adjustably moved up or down and positioned vertically and perpendicular to the vertical outside leg portions 16 and 17. Rotatable mounting sleeves 35-35 and associated stand-off wall abutment struts 27 and 28 may also be rotatably moved back and forth in a horizontal frame so as to come into friction contact with the building support wall 26 at an appropriate position selected by the operator and be locked into that selected position by means of the provided friction lock means 36-36. The dashed phantom line rendition of a stand-off wall abutment strut 28 in FIG. 2 illustrates how the slidably adjustable mounting sleeve 35 allows the wall abutment strut 28 to be moved slidably up and-down the outside vertical leg portions 17 and rotated around the said leg portion 17 back and forth in a horizontal plane to allow the operator-workman to adapt the combination step-ladder and bridge-crane structure 11 to service a wider variety of buildings that can be serviceable by a step-ladder and bridge-crane st ucture with only rigid stand-off wall abutment struts 27 and 28.

Another slightly varied embodiment of the Invention suggested in one particular form in FIG. 2 involves a portable step-ladder and bridge-crane structure 11 in which the horizontally positioned stand-off wall abutment struts 27 and 28 are adapted for adjustable length by providing each of the said struts with a telescoping extension member 37 together with a manual friction lock 38 on each wall abutment strut 27 and 28 adapted to lock and fix the telescopic extension members 37-37 into a position selected by the workman-user to improve the stability of the ladder and bridge-crane assembly 11 when it is at a controlled spaced apart position from the building wall 26. Once again the dashed phantom line rendition shows one possible way in which a telescoping extension member 37 may be employed to lengthen or shorten the wall abutment strut 28 which will meet with and engage a greater variety of building walls that may confront an operator-workman. Another alternate embodiment of the step-ladder and bridge-crane structure 11 contemplated in the chosen illustration of FIG. 2 employs swivelable adjustable friction secured foot members 39-39 on the ends of the stand-off wall abutment struts 27 and 28 in order to prevent the bridge-crane structure 11 from slipping laterally with respect to the abutting building 26 while a load is being lifted to the roof of the building. The friction secured foot members 39-39 would be particularly suited for use in conjunction with the variation of the bridge-crane structure 11 already described in which the stand-off wall abutment struts 27 and 28 ro tate and swivel on the adjustable mounting sleeves 35-35. The rotatable mounting sleeves 35-35 create the probability that the wall abutment struts 27 and 28 would meet the wall of the building being serviced at an angle different from a right angle, and should that building wall surface be in the least bit smooth or slick, the step-ladder and bridge-crane structure 11 would have a tendency to slide laterally over the wall surface necessitating some sort of stabilizing structure such as the said friction secured foot members 39-39.

One of the goals of the portable step-ladder and bridge-crane structure 11 is to provide a means by which people as well as materials and equipment may gain access to the rooftop of a building and although the nearly vertical step ladder 18 is spaced apartand held away from the wall of the building 26 by the wall abutment struts 27 and 28, the standoff distance is contemplated to be small enough to permit the operatoruser to step from the topmost step rung 21 or the cross brace 25 to the roof of the building being serviced while holding onto the top center horizontal portions 22 and 23 of inverted U-shaped bridge-crane members 12 and 13. However, the lifting of some larger and bulkier equipment may necessitate a size of portable step ladder and bridge-crane structure 11 that would result in having a load lift passageway space 29 of such size that it would be difficult for the workman-user to get from the top of the vertically positioned step ladder 18 to the roof of the adjoining building. In the case of such a large load passageway space 29, a folding step assembly 40 would be employed to bridge the load passageway space 29 between the top of the vertical support step ladder 18 and the roof of the building to be serviced. The folding step assembly 40 would consist of a pair of parallel spaced apart step supporting arms 41-41 having a length somewhat longer than the stand-off wall abutment struts 27 and 28 and somewhat shorter than the length of the: top center horizontal por tions 22 and 23 of the inverted U-shaped bridge-crane members 12 and 13. A transverse step platform 42 would be mounted between the step supporting arms 41-41 at right angles at intermediate points near the mid-point in the length of each of said step supporting arms 41-41 which would form an H-shape with the transverse step platform 42. The ends of the step platform support arms 41-41 are connected to intermediate points on the outside vertical leg portions 16 and 17 of the inverted Ushaped bridge-crane members 12 and 13 by toggle hinges 43-43 which permit the step supporting arms 41-41 and the transverse step platform 42 to be freely rotated between a vertical folded out-of the-way position roughly parallel to the vertically positioned step ladder l8 and a horizontal position with the unhinged ends of the step supporting arms 41-41 being supported by the upper wall sill of the building being serviced while the other ends of the hinged step supporting arms 41-41 are being supported by the toggle hinged connections 43-43 at the selected points on the vertical leg portions 16 and 17. There would also be provided a folding step draw line 44 attached to the inside edge of the transverse step platform 42 to allow the operator-user to raise said folding step into a horizontal position while he is standing on the roof of the adjacent building as suggested by the illustration in FIG. 3. The folding step assembly 40 could also be hinged in a manner so that the step would hang on the outside of the nearly vertical step ladder 18 instead of on the inside as suggested by FIG. 1 so that the operator-user could flip over the transverse step plat form 42 as he climbs up the vertical step ladder 18.

Since all buildings to be serviced by the portable step-ladder and bridge-crane: structure 11 will not have wall sills of the same height to support the free ends of the step supporting arms 41-41, to make the folding step assembly 40 a useful working part, it may be necessary to adapt the folding step assembly 40 so that it freely adjusts to a variety of building heights. This may be done by fabricating the toggle hinges 43-43 sup porting the step support arms 44 in the form of tubular shaped sliding adjustable clamps 45-45 with manual friction locks 46-46 built into the sliding adjustable clamps 45-45 so that the folding step 40 can be raised or lowered as necessary to permit the folding step platform 42 to sit level with the upper level wall sill of the building when the step supporting arms 41-41 and associated step platform 42 are rotated up to the horizontal operative position and locked into place to keep from slipping with manual friction locks 46-46. The sliding adjustable clamps 4-5-45 thereby make the folding foot step assembly 40 usable with any size of building.

The embodiment of the portable step-ladder and bridge-crane structure 11 as shown for illustrative purposes only in FIG. 1 of the Drawings where the nearly vertical step-ladder 18 is an integral part of the unitary step-ladder and bridge-crane structure 11, may be too large and too bulky for the workman with only a small operation of working on building rooftops to fit into his pick-up; and further, the workman-user or husband who would find weekend use for such a bridge-crane structure may find it difficult to justify purchasing a unitary step-ladder and bridge-crane structure if he already possesses a conventional wall-leaning step ladder. Therefore, another variation and embodiment of the invention might look like the illustration in FIG. 4 in which the step-ladder and bridge-crane structure 11 would consist of two major attachable-removable parts: a portable bridge-crane device 47 and a portable attachable-detachable step ladder 48. The joining means for the portable bridgecrane device 47 and the portable attachable-detachable step ladder 48 is a sleeve-socket receiving means 49 on the outside end of each of said bridge-crane member 12 and 13, said sleeve-socket receiving means 4949 being adapted to fit over and receive the upper ends of the vertical side rails of the attachable-detachable step ladder 48. The sleeve socket receiving means 49-49 may be designed so that the ends of any conventional step ladder may be used in conjunction with the attachable-detachable portable bridge-crane structure 47 or the sleeve-socket receiving means 49-49 may be designed in a specialized configuration to fit the upper ends of the vertical side rails of a particular style of attachable-detachable step ladder 48 to provide a snugger and more secure fit be tween attachable-detachable bridge-crane structure 47 and attachable-detachable step ladder 48. Being in a more collapsible form, the step-ladder and bridgecrane structure 11 made from a separable bridge-crane device 47 and an attachable-detachable step ladder 48 will store more compactly and neatly than the previously described unitary embodiment. The attachabledetachable bridge-crane device 47 may also be used in conjunction with the various versions of the stand-off wall abutment struts 27 and 28 and together with the folding step assembly 40 to allow greater versatility and usefulness in a detachable step-ladder and bridge-crane structure device.

In some instances the workmen using the apparatus described herein will have available already established means of admission and exit to the roof of the building where equipment is to be installed and may need this bridge-crane structure temporarily only to lift equipment that is to be installed to the roof of the building. In such instances a first vertical support means is needed in lieu of the attachable-detachable step ladder 48 to support the end of the bridgecrane structure that is away from the wall. However, when the ladder is not needed as a means of gaining access to the roof of the adjacent building the alternate first support means, which may be manufactured or improvised by the user, can be a much simpler and more easily handled structure with resulting savings in cost, time and effort.

In order to provide for user-customers with this kind of circumstances the manufacturer of the bridge-crane device described herein may prefer to fabricate a version of the invention that includes only the transverse top cap portion 47 of the bridge crane as illustrated in FIG. 5 of the drawings herein. The structural portions of the bridge-crane cap 47 could be substantially identical with the structure illustrated in solid lines in FIGS. 4 and 5, as described in the preceding disclosure paragraphs and as claimed in part of Claim No. 8 except that attachable-removable step ladder 48 is deleted and the outside legs 16 and 17 of bridge crane members 12 and 13 are provided with suitably shaped sleeve-socket receiving means 49-49 that can attachablydetachably receive any type of suitable alternate first vertical support means that the user customer may choose to provide.

OPERATION In operation, the workman-user unloads the portable step-ladder supported bridge-crane structure 11 from his vehicle at the work site of the building to be serviced and carries it over to the building and leans the step-ladder and bridge-crane structure against the outside of the building walls in the manner of a conventional step ladder except that the free ends of the spaced apart stand-off wall abutment struts 27 and 28 engage and rest against the outside building wall surface 29 to help support the weight of the bridge-crane structure 11 while the turned down inside ends 14 and 15 of inverted U-shaped bridge-crane members 12 and 13 engage and are supported by the roof of the building to be serviced. In this way a kind of load support frame is erected with the bottom ends of the upright side rails 19 and 20 of the vertical step ladder l8 and the bottom portions of the inside ends 14 and 15 serving as the leg support braces when a heavy load of equipment or materials is lifted from the center of the bridge-crane structure 1 1 at the pulley-hoist mounting support structure location 24 through load lift passageway space 29. The bottom ends of the upright side rails 19 and 20 and the stand-off wall abutment struts 27 and 28 support the step-ladder and bridge-crane structure 11 when an operator-workman climbs up the nearly vertical step ladder 18. If the workman-user is using the two-piece embodiment of the step-ladder and bridge-crane structure 11 that consists of the portable bridge-crane device 47 and the portable attachable-detachable step ladder 48, the workman need only insert the upper ends of the upright side rails 19 and 20 of the portable attachable-detachable step ladder 48 into the bottom ends of the sleeve socket receiving means 4949 on the outside ends of the inverted Ushaped bridge-crane members 12 and 13 to make the combined step-ladder supported bridge-crane structure 11 which can be quickly and easily set into place against the wall of the building to be serviced 26.

By adjusting the manual friction lock means 36-36 on the rotatably and slidably adjustable mounting sleeves 3535, the stand-off wall abutment struts 27 and 28 may be adjusted and adapted in height and angle to more securely engage and rest against the building wall 26. The spaced-apart wall abutment struts 27 and 28 may be adjusted for length by operating manual friction locks 3838 that regulate the length of the stand-off wall abutment struts 27 and 28 by allowing wall abutment strut telescoping extension members 37 and 37 to be moved out to meet with and engage the building wall 26. The swivelably adjustable friction secured foot members 3939 on the ends of the stand-off wall abutment struts 27 and 28 will turn and meet with and engage the building wall surface 26 automatically as the free ends of the stand-off wall abutment struts 27 and 28 get close and come into contact with the building to be serviced to provide secure footing against possible lateral motion of the stepladder supported bridge-crane structure 11.

To raise a load of materials or equipment onto the roof of a building at the work site with the step-ladder supported bridge-crane structure ll, the operator-user secures the load line 34 securely around the materials to be hoisted and then pulls on the other end of the load line 34 and by means of block and tackle apparatus 31, lifts the load of materials high enough to clear the edge of the wall sill of the building 26 when the inverted L- shaped load hoist boom arm 30 is swiveled over the roof of the building as suggested in FIGS. 4 and 5 of the Drawings. The load is then moved over and deposited on the roof of the adjoining building by rotating load hoist boom arm 30. Loads of materials and equipment may also be taken off of the roof of the building being worked on by simply reversing the process and swinging the load hoist boom arm 30 in the direction from the roof of the building over load clearance passageway 29.

The workman'operator may ascend to the roof of the adjacent building by climbing up the step rungs 21-21 on nearly vertical step ladder 18 and stepping across the load passageway space 29 at the top of the stepladder supported bridge-crane structure 11 onto the building roof by holding onto the top center horizontal portions 22 and 23 of inverted U-shaped bridge-crane members 12 and 13. If the load passageway space 29 is too broad to be crossed by merely stepping across, the workman-operator may decide to raise the folding step assembly 40 by means of folding step draw line 44 which would bridge the load lift passageway 29 with the parallel spaced apart step supporting arms 41-41 having one set of ends hinged by means of toggle hinges 43-43 mounted on the outside legs 16 and 17 of the inverted U-shaped bridge-crane members 12 and 13 and the other ends of step supporting arms 4141 resting on the top edge of the outside building wall 26. The toggle hinges 4343 and the ends of the step supporting arms 41-41 may be moved along the length of the outside leg portions 16 and 17 of the inverted U-shaped bridge-crane members 12 and 13 to match the height of the top edge of the wall of the associated building 26 and thus level the folding step assembly 40 by adjusting the manual friction locks 46-46 on the tubular shaped sliding adjustable clamps 45-45 that are fitted around the outside lower leg portions 16 and 17. The operatoruser may then cross the load passageway 29 by stepping on the transverse step platform 42 mounted between the parallel step supporting arms 4141.

The step-ladder supported bridge-crane structure 11 is readied for loading on the users vehicle by folding down the folding step assembly 40 and folding and telescoping in the adjustable stand-off wall abutment struts 27 and 28, and by taking apart the portable bridgecrane device 47 and the attachable-detachable step ladder 48 in the two-piece embodiment of the Invention. Thus compacted, the step-ladder supported bridge-crane structure 11 is ready for loading and transport back to the shop.

ADVANTAGES OF THE INVENTION In the foregoing description of the structure and operation of the Invention set forth herein, a number of advantages have been claimed for the apparatus and others will be readily apparent to persons skilled in the art. One major advantage of the invention is that it provides a simple, quick portable manually operated means of lifting building materials, equipment and heavy loads to the roof tops of small buildings where construction, equipment installation or repair work is to be done.

Another advantage of the invention is that it provides a portable, quickly and easily erected and operated hoist for lifting heavy air compressors for air conditioning systems to the rooftops of small buildings where such equipment is to be installed, as well as for lifting such equipment down off of the building when it is no longer needed.

Still another notable advantage of this invention is that the attachabledetachable bridge-crane device may utilize an existing building as one convenient and readily available vertical support means and an ordinary step ladder, whether it be 8 feet or 24 or more feet in length, as a second convenient vertical support means to give the hoisting structure a secure enough footing for the lifting of heavy objects,

Another advantage of the invention is that it provides a load lifting bridge-crane structure of such weight and design as to permit a single workman to load the bridge-crane structure into a pick-up truck for trans portation and for said single workman to place the bridge-crane structure into position at the work site and by using the swivel hoist means on the top center of the bridge-crane structure to lift and place materials and machinery onto an adjacent building.

A futher advantage of the invention is that it is provided with adjustable stand-off wall abutment strut means to control the amount of distance and space between the vertical ladder support and the wall of the building to be serviced as well as to provide lateral bracing support for the entire bridge-crane structure while a load is lifted to the top or while a workman is ascending the ladder.

Still another advantage of the invention is that it provides a swivelable or rotatable hoist support means that is so positioned in the top of the step'ladder supported bridge-crane structure that the equipment load can be lifted straight up from the ground without dragging it against the building or other structures such as the step ladder with means of rotating, the suspended load to a position over the building roof where it can be lowered with a minimum of struggle and inconvenience and threat of injury to the operator-workman. The load may be lifted straight up in a safe efficient manner through a load passageway space opening in the center of the step-ladder supported bridge-crane structure.

One more advantage of the invention is that it provides, in association with the bridge-crane structure, a hinged folding step platform that hangs folded in an out-ofthe-way position while load lifting work is per formed and that can be manually, quickly and easily unfolded and lifted into a horizontal working position when a workman needs a safe and convenient way to step across the space between the top of the ladder and the rooftop of the building to be serviced.

Although this specification describes but a few embodiments of the Invention with certain applications thereof, it should be understood that structural or material rearrangements of adequate or equivalent parts, substitutions of equivalent functional elements and other modifications in structure can be made and other applications devised without departing from the spirit and scope of my Invention. I therefore desire that the description and drawings herein be regarded as only an illustration of my Invention and that the Invention be regarded as limited only as set forth in the following claims, or as required by the prior art.

I claim:

1. A portable bridge-crane device structure designed to be supported at a distance above ground between an associated step ladder as one support means and the wall and roof of a building as a second support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed,- said ladder supportable bridge-crane structure comprising:

A. a pair of spaced apart generally broad inverted U- shaped bridge-crane members 1. fabricated from a strong tubular material,

2. with one end of said bridge-crane members supported by a vertically positioned step ladder, and

3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building,

4. with the horizontal portions of the inverted U- shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that they can provide parallel hand rail support means for persons stepping across the distance from the top of the associated step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulleyhoist means;

B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship;

C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain an asso-' ciated ladder supported at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts 1. having a length approximately 55 to 80% of the length of the bridge-crane member such that, when in use, the stand-off wall abutment struts rest against the wall of the building when the bridge-crane members are at rest on the roof of the building on which work is to be performed.

2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U- shaped bridge-crane membersuch that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the crossbrace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced;

D. a swivel means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U-shaped bridge-crane member;

E. an inverted L-shaped load hoist boom arm rotatably mounted in the swivel mount means; and

F. a pulley block and tackle and load lifting line suspended from the load hoist boom arm.

2. A portable combination step ladder and bridgecrane device structure designed to be supported at a distance above ground between a step ladder as one support means and the wall and roof of a building as a second support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed, said ladder supported birdge-crane structure comprising:

A. a pair of spaced apart generally broad inverted U- shaped bridge-crane members 1. fabricated from a strong tubular material,

2. with the outside vertical ends of each of said bridge-crane members being extended to form a vertically positioned step ladder provided with a plurality of spaced apart step rungs, with said bridge-crane structure and said step ladder vertical support structure forming a combination unitary structure,

3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building,

4. with the horizontal portions of the inverted U- shaped bridge-crane members being longer than the inside vertical legs of said bridge-crane members such that they can provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support stepladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means;

B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship;

C. a conventional step-ladder fabricated from strong metal tubing adapted to serve as a vertical support for the outside end of said bridge-crane structure with said step-ladder having 1. spaced apart left and right upright side rails that are elongated extensions of the outside vertical portions of the pair of inverted U-shaped bridgecrane members, and

2. with a plurality of spaced apart ladder step rungs mounted transversely between the upright side rails of said step-ladder;

D. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain the vertical support step-ladder at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts 1. having a length approximately 55 to of the length of the horizontal portion of each bridgecrane member such that, when in use, the standoff wall abutment struts rest against the wall of the building when the inside ends of the bridgecrane members are at rest on the roof of the building on which work is to be performed,

2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U- shaped bridge-crane member such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the crossbrace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced;

E. a swivel mount means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U shaped bridge-crane member;

F. an inverted L shaped load hoist boom arm rotatably mounted in the swivel mount means; and

G. a block and tackle apparatus suspended from the load hoist boom arm and adapted to lift materials and equipment to the top of the building being served, with said block and tackle including 1. a crown block,

2. a traveling block, and 3. an appropriate length of load line to provide load lifting means.

3. The portable combination step-ladder and bridgecrane structure described in claim 2 with each of the horizontally positioned spaced apart stand-off wall abutment struts being rotatably and slidably and adjustably mounted at an intermediate point on a vertical portion of the outside legs of the U-shaped bridge crane members by provision of a rotatably and slidably adjustable mounting sleeve fitted around said vertical tubular leg portion of the U-shaped bridge-crane member with provision of manually adjusted friction locks adapted to secure the setting of said slidable adjustable sleeve such that each of the attached stand-off wall abutment struts can be adjustably moved up or down and positioned vertically with respect to the vertical support leg portion of each bridge-crane member and such as to permit said rotatable mounting sleeve and attached stand-off wall abutment struts to be rotatably moved back and forth in a horizontal plane so as to come into friction contact with the building support wall at a selected position and be locked in that selected position by means of the provided friction locks.

4. The portable combination step ladder and bridgecrane structure described in claim 2 in which each of the horizontally positioned spaced-apart stand-off wall abutment struts are adapted for adjustable length of the wall engaging strut by providing each of said struts with a telescoping extension member together with provision of a friction lock on each strut member adapted to lock the telescopic extension member into a selected position in order to provide improved stability to the ladder and bridge-crane assembly at a controlled spaced apart position from the building wall.

5. The portable combination step ladder and bridgecrane structure described in claim 2 in which each of the horizontally positioned spaced-apart stand'off wall abutment struts are provided with swivelable adjustable friction secured foot members in order to prevent the bridge-crane structure from slipping laterally with respect to the abutting building while a load is being lifted to the roof of the building.

6. The portable combination step ladder and bridgecrane device described in claim 2 together with a folding step to bridge the space between the top of the vertical support step-ladder and roof of the building to be serviced, said folding step having A. a pair of parallel spaced apart step supporting arms of a length somewhat greater than the length of the stand-off wall abutment struts and somewhat shorter than the length of the horizontal portion of the inverted U-shaped bridge-crane members,

B. a transverse step platform mounted between said parallel step supporting arms at intermediate points near the midpoint in the length of each of said step supporting arms, and C. with said step platform support arms being connected to intermediate points on the outside vertical portion of the inverted U-shaped bridge-crane members by toggle hinges such as to permit the folding step platform to be rotated between a vertical folded out out-ofthe-way position generally parallel to the stepladder and vertical portion of the inverted U- shaped bridge-crane members and alternately rotated upward to a horizontal position with one end of said hinged folding step and step supporting arms being supported on the upper wall sill of the building being serviced and the other ends of the hinged step supporting arms being supported by hinge connections from selected points on the outside vertical portion of inverted U-shaped bridgecrane members, and having a folding step draw line attached to the inside edge of the folding step to permit the operator to raise said folding step into a horizontal position while the operator is standing on the roof of the adjacent building.

7. The portable combination step'ladder and bridgecrane-structure described in claim 6 in which one end of the toggle hinges supporting the hinged folding step is fabricated in the form of a tubular shaped slidingadjustable clamp with friction lock devices built into each of said clamp toggle hinges so that said folding step can be raised or lowered as necessary to permit the folding step platform to sit level with the upper wall sill of the building when the folding step is rotated up to its horizontal operative position.

8. A portable bridge-crane device structure designed to be supported at a distance above ground between an attachable-detachable step ladder as one vertical support means and the wall and roof of a building as a sec ond vertical support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed,-said ladder supported bridge-crane structure comprising:

A. a pair of spaced apart generally broad inverted U- shaped bridge-crane members 1. fabricated from a strong tubular material,

2. with one end of each of said bridge-crane members being provided with a sleeve-socket receiving means adapted to fit over and receive the upper ends of the vertical side rails of an attachabledetachable step ladder,

3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building, and

4. with the horizontal portions of the inverted U shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that said horizontal portions can provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means; B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship; C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain the vertical support step-ladder at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts 1. having a length approximately 55 to 80% of the length of the horizontal portion of each bridgecrane member such that, when in use, the standoff wall abutment struts rest against the wall of the building when the inside ends of the bridgecrane members are at rest on the roof of the building on which work is to be performed, and

2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U- shaped bridge-crane member such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced;

D. a swivel mount means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U shaped bridge-crane member;

E. an inverted L shaped load hoist boom arm rotatably mounted in the swivel mount means; and

F. a block and tackle apparatus suspended from the load hoist boom arm and adapted to lift materials and equipment to the top of the building being served, with said block and tackle including 1. a crown block,

2. a travelling block, and 3. an appropriate length of load line to provide load lifting means.

9. The portable combination step-ladder and bridgecrane structure described in claim 8 with each of the horizontally positioned spaced apart stand-off wall abutment struts being rotatably and slidably and adjustably mounted at an intermediate point on a vertical portion of the outside legs of the U-shaped bridgecrane members by provision of a rotatably and slidably adjustable mounting slecve fitted around said vertical tubular leg portion of the U-shaped bridge-crane member with provision of manually adjusted friction locks adapted to secure the setting of said slidablc adjustable sleeve such that each of the attached stand-off wall abutment struts can be adjustably moved up or down and positioned vertically with respect to the vertical support leg portion of each bridge-crane member and such as to permit said rotatable mounting sleeve and attached stand-off wall abutment struts to be rotatably moved back and forth in a horizontal plane so as to come into friction contact with the building support wall at a selected position and be locked in that selected position by means of the provided friction locks.

10. The portable combination step ladder and bridgecrane structure described in claim 8 in which each of the horizontally positioned spaced-apart stand-off wall abutment struts are adapted for adjustable length of the wall engaging strut by providing each of said struts with a telescoping extension member together with provision of a friction lock on each strut member adapted to lock the telescopic extension member into a selected position in order to provide improved stability to the ladder and bridge-crane assembly at a controlled spaced apart position from the building wall.

1 l. The portable combination step ladder and bridgecrane structure described in claim 8 in which each of the horizontally positioned spaced-apart stand-off wall abutment struts are provided with swivelable adjustable friction secured foot members in order to prevent the bridge-crane structure from slipping laterally with respect to the abutting building while a load is being lifted to the roof of the building.

12. The portable combination step ladder and bridgecrane device described in claim 8 together with a folding step to bridge the space between the top of the associated vertical support attachable-detachable stepladder and roof of the building to be serviced, said folding step having A. a pair of parallel spaced apart step supporting arms of a length somewhat greater than the length of the stand-off wall abutment struts and somewhat shorter than the length of the horizontal portion of the inverted U shaped bridge-crane members,

B. a transverse step platform mounted between said parallel step supporting arms atintermediate points near the midpoint in the length of each of said step supporting arms, and

C. with said step platform support arms being connected to intermediate points on the outside vertical portion of the inverted U-shaped bridge-crane members by toggle hinges such as to permit the folding step platform to be rotated between a vertical folded out-of-the-way position generally parallel to the associated attachable-detachable stepladder and vertical portion of the inverted U- shaped bridge-crane members and alternately rotated upward to a horizontal position with one end of said hinged folding step and step supporting arms being supported on the upper wall sill of the building being serviced and the other ends of the hinged step supporting arms being supported by hinge connections from selected points on the outside vertical portion of inverted U-shaped bridgecrane members, and having a folding step draw line attached to the inside edge of the folding step to permit the operator to raise said folding step into a horizontal position while the operator is standing on the roof of the adjacent building.

13. The portable combination step-ladder and bridge-crane structure described in claim 12 in which one end of the toggle hinges supporting the hinged folding step is fabricated in the form of a tubular shaped sliding-adjustable clamp with friction lock devices built into each of said clamp toggle hinges so that said folding step can be raised or lowered as necessary to permit the folding step platform to sit level with the upper wall sill of the building when the folding step is rotated up to its horizontal operative position.

14. A portable bridge-crane cap structure designed to be supported at a distance above ground between an attachable-detachable support structure provided by the user as a first vertical support means and the wall and roof of a building as a second vertical support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed, said bridge-crane cap structure comprising:

A. a pair of spaced apart generally broad inverted U- shaped bridge-crane members 1. fabricated from a strong tubular material,

2. with one end of each of said bridge-crane members being provided with a sleeve-socket receiving means adapted to fit over and receive the upper ends of the vertical side rails of an attachable-detachable first support means,

3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building, and

4. with the horizontal portions of the inverted U shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that said horizontal portions can provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means;

B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship;

C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain the vertical support step-ladder at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts 1. having a length approximately 55 to 80% of the length of the horizontal portion of each bridgecrane member such that, when in use, the standoff wall abutment struts rest against the wall of the building when the inside ends of the bridgecrane members are at rest on the roof of the building on which work is to be performed, and

2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U- shaped bridge-crane member such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced;

D. a swivel mount means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U-shaped bridge-crane member;

E. an inverted L-shaped load hoist boom arm rotatably mounted in the swivel mount means; and

F. a block and tackle apparatus suspended from the load hoist boom arm and adapted to lift materials and equipment to the top of the building being served, and said block and tackle including ii. a crown block,

2. a travelling block, and 3. an appropriate length of load line to provide load lifting means.

15. The portable combination step ladder and bridgecrane device described in claim 14 together with a folding step to bridge the space between the top of the associated vertical support attachable-detachable stepladder and roof of the building to be serviced, said folding step having A. a pair of parallel spaced apart step supporting arms of a length somewhat greater than the length of the stand-off wall abutment struts and somewhat shorter than the length of the horizontal portion of the inverted U-shaped bridge-crane members,

B. a transverse step platform mounted between said parallel step supporting arms at intermediate points near the midpoint in the length of each of said step supporting arms, and

C. with said step platform support arms being connected to intermediate points on the outside vertical portion of the inverted U-shaped bridge-crane members by toggle hinges such as to permit the folding step platform to be rotated between a vertical folded out-of-the-way position generally parallel to the associated attachable-detachable support structure and vertical portion of the inverted U shaped bridge-crane members and alternately rotated upward to a horizontal position with one end of said hinged folding step and step supporting arms being supported on the upper wall sill of the building being serviced and the other ends of the hinged step supporting arms being supported by hinge connections from selected points on the outside vertical portion of inverted U-shaped bridgecrane members, and having a folding step draw line attached to the inside edge of the folding step to permit the operator to raise said folding step into a horizontal position while the operator is standing on the roof of the adjacent building.

16. The portable combination step-ladder and bridge-crane structure described in claim 14 in which one end of the toggle hinges. supporting the hinged folding step is fabricated in the form of a tubular shaped sliding-adjustable clamp with friction lock devices built into each of said clamp toggle hinges so that said folding step can be raised or lowered as necessary to permit the folding step platform to sit level with the upper wall sill of the building when the folding step is rotated up to its horizontal operative position. 

1. A portable bridge-crane device structure designed to be supported at a distance above ground between an associated step ladder as one support means and the wall and roof of a building as a second support means together with a swivel mounted pulleyHoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed,-said ladder supportable bridge-crane structure comprising: A. a pair of spaced apart generally broad inverted U-shaped bridge-crane members
 1. fabricated from a strong tubular material,
 2. with one end of said bridge-crane members supported by a vertically positioned step ladder, and
 3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building,
 4. with the horizontal portions of the inverted U-shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that they can provide parallel hand rail support means for persons stepping across the distance from the top of the associated step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means; B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship; C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain an associated ladder supported at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts
 1. having a length approximately 55 to 80% of the length of the bridge-crane member such that, when in use, the stand-off wall abutment struts rest against the wall of the building when the bridge-crane members are at rest on the roof of the building on which work is to be performed.
 2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U-shaped bridge-crane member-such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross-brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced; D. a swivel means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U-shaped bridge-crane member; E. an inverted L-shaped load hoist boom arm rotatably mounted in the swivel mount means; and F. a pulley block and tackle and load lifting line suspended from the load hoist boom arm.
 2. with one end of each of said bridge-crane members being provided with a sleeve-socket receiving means adapted to fit over and receive the upper ends of the vertical side rails of an attachable-detachable step ladder,
 3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building, and
 2. a travelling block, and
 2. a traveling block, and
 2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U-shaped bridge-crane member - such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced; D. a swivel mount means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U shaped bridge-crane member; E. an inverted L shaped load hoist boom arm rotatably mounted in the swivel mount means; and F. a block and tackle apparatus suspended from the load hoist boom arm and adapted to lift materials and equipment to the top of the building being served, with said block and tackle including
 2. with one end of said bridge-crane members supported by a vertically positioned step ladder, and
 2. with the outside vertical ends of each of said bridge-crane members being extended to form a vertically positioned step ladder provided with a plurality of spaced apart step rungs, with said bridge-crane structure and said step ladder vertical support structure forming a combination unitary structure,
 2. with a plurality of spaced apart ladder step rungs mounted transversely between the upright side rails of said step-ladder; D. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain the vertical support step-ladder at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts
 2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U-shaped bridge-crane member-such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross-brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced; D. a swivel means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U-shaped bridge-crane member; E. an inverted L-shaped load hoist boom arm rotatably mounted in the swivel mount means; and F. a pulley block and tackle and load lifting line suspended from the load hoist boom arm.
 2. A portable combination step ladder and bridge-crane device structure designed to be supported at a distance above ground between a step ladder as one support means and the wall and roof of a building as a second support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed, - said ladder supported birdge-crane structure comprising: A. a pair of spaced apart generally broad inverted U-shaped bridge-crane members
 2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U-shaped bridge-crane member - such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross-brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced; E. a swivel mount means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U shaped bridge-crane member; F. an inverted L shaped load hoist boom arm rotatably mounted in the swivel mount means; and G. a block and tackle apparatus suspended from the load hoist boom arm and adapted to lift materials and equipment to the top of the building being served, with said block and tackle including
 2. a travelling block, and
 2. being mounted on and at approximately a right angle to the outside vertical portion of the inverted U-shaped bridge-crane members at an intermediate point approximately two to three feet below the horizontal portion of said inverted U-shaped bridge-crane member - such that the space enclosed between said spaced apart pair of stand-off wall abutment struts and the cross brace and the wall of the building upon which work is to be performed constitutes a load passageway through which materials and equipment may be lifted in moving such materials to the roof of the building being serviced; D. a swivel mount means attached to one of the bridge-crane members at an intermediate point near the center of the horizontal portion of the inverted U-shaped bridge-crane member; E. an inverted L-shaped load hoist boom arm rotatably mounted in the swivel mount means; and F. a block and tackle apparatus suspended from the load hoist boom arm and adapted to lift materials and equipment to the top of the building being served, and said block and tackle including
 2. with one end of each of said bridge-crane members being provided with a sleeve-socket receiving means adapted to fit over and receive the upper ends of the vertical side rails of an attachable-detachable first support means,
 3. the second end of said bridge-crane members being adapted with structural means To rest upon and engage the roof-top of a building, and
 3. The portable combination step-ladder and bridge-crane structure described in claim 2 with each of the horizontally positioned spaced apart stand-off wall abutment struts being rotatably and slidably and adjustably mounted at an intermediate point on a vertical portion of the outside legs of the U-shaped bridge-crane members by provision of a rotatably and slidably adjustable mounting sleeve fitted around said vertical tubular leg portion of the U-shaped bridge-crane member with provision of manually adjusted friction locks adapted to secure the setting of said slidable adjustable sleeve such that each of the attached stand-off wall abutment struts can be adjustably moved up or down and positioned vertically with respect to the vertical support leg portion of each bridge-crane member and such as to permit said rotatable mounting sleeve and attached stand-off wall abutment struts to be rotatably moved back and forth in a horizontal plane so as to come into friction contact with the building support wall at a selected position and be locked in that selected position by means of the provided friction locks.
 3. an appropriate length of load line to provide load lifting means.
 3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building,
 3. the second end of said bridge-crane members being adapted with structural means to rest upon and engage the roof-top of a building,
 3. an appropriate length of load line to provide load lifting means.
 3. an appropriate length of load line to provide load lifting means.
 4. with the horizontal portions of the inverted U shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that said horizontal portions can provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means; B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship; C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain the vertical support step-ladder at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts
 4. with the horizontal portions of the inverted U-shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that they can provide parallel hand rail support means for persons stepping across the distance from the top of the associated step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means; B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship; C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain an associated ladder supported at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts
 4. with the horizontal portions of the inverted U-shaped bridge-crane members being longer than the inside vertical legs of said bridge-crane memberS such that they can provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means; B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship; C. a conventional step-ladder fabricated from strong metal tubing adapted to serve as a vertical support for the outside end of said bridge-crane structure with said step-ladder having
 4. The portable combination step ladder and bridge-crane structure described in claim 2 in which eaCh of the horizontally positioned spaced-apart stand-off wall abutment struts are adapted for adjustable length of the wall engaging strut by providing each of said struts with a telescoping extension member together with provision of a friction lock on each strut member adapted to lock the telescopic extension member into a selected position in order to provide improved stability to the ladder and bridge-crane assembly at a controlled spaced apart position from the building wall.
 4. with the horizontal portions of the inverted U shaped bridge-crane members being longer than the vertical legs of said bridge-crane members such that said horizontal portions can provide parallel hand rail support means for persons stepping across the distance from the top of the vertical support step-ladder to the roof of a building and also provide a suitably positioned support for mounting a pulley-hoist means; B. at least one cross brace means extending from one of the spaced apart and parallel bridge-crane members to the other bridge-crane member to hold said bridge-crane members in a parallel spaced apart relationship; C. a pair of horizontally positioned, spaced apart stand-off wall abutment struts to maintain the vertical support step-ladder at a controlled distance from the wall of the building, with each of said stand-off wall abutment struts
 5. The portable combination step ladder and bridge-crane structure described in claim 2 in which each of the horizontally positioned spaced-apart stand-off wall abutment struts are provided with swivelable adjustable friction secured foot members in order to prevent the bridge-crane structure from slipping laterally with respect to the abutting building while a load is being lifted to the roof of the building.
 6. The portable combination step ladder and bridge-crane device described in claim 2 together with a folding step to bridge the space between the top of the vertical support step-ladder and roof of the building to be serviced, said folding step having A. a pair of parallel spaced apart step supporting arms of a length somewhat greater than the length of the stand-off wall abutment struts and somewhat shorter than the length of the horizontal portion of the inverted U-shaped bridge-crane members, B. a transverse step platform mounted between said parallel step supporting arms at intermediate points near the midpoint in the length of each of said step supporting arms, and C. with said step platform support arms being connected to intermediate points on the outside vertical portion of the inverted U-shaped bridge-crane members by toggle hinges such as to permit the folding step platform to be rotated between a vertical folded out out-of-the-way position generally parallel to the step-ladder and vertical portion of the inverted U-shaped bridge-crane members - and alternately rotated upward to a horizontal position with one end of said hinged folding step and step supporting arms being supported on the upper wall sill of the building being serviced and the other ends of the hinged step supporting arms being supported by hinge connections from selected points on the outside vertical portion of inverted U-shaped bridge-crane members, and having a folding step draw line attached to the inside edge of the folding step to permit the operator to raise said folding step into a horizontal position while the operator is standing on the roof of the adjacent building.
 7. The portable combination step-ladder and bridge-crane structure described in claim 6 in which one end of the toggle hinges supporting the hinged folding step is fabricated in the form of a tubular shaped sliding-adjustable clamp with friction lock devices built into each of said clamp toggle hinges so that said folding step can be raised or lowered as necessary to permit the folding step platform to sit level with the upper wall sill of the building when the folding step is rotated up to its horizontal operative position.
 8. A portable bridge-crane device structure designed to be supported at a distance above ground between an attachable-detachable step ladder as one vertical support means and the wall and roof of a building as a second vertical support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed,-said ladder supported bridge-crane structure comprising: A. a pair of spaced apart generally broad inverted U-shaped bridge-crane members
 9. The portable combination step-ladder and bridge-crane structure described in claim 8 with each of the horizontally positioned spaced apart stand-off wall abutment struts being rotatably and slidably and adjustably mounted at an intermediate point on a vertical portion of the outside legs of the U-shaped bridge-crane members by provision of a rotatably and slidably adjustable mounting sleeve fitted around said vertical tubular leg portion of the U-shaped bridge-crane member with provision of manually adjusted friction locks adapted to secure the setting of said slidable adjustable sleeve such that each of the attached stand-off wall abutment struts can be adjustably moved up or down and positioned vertically with respect to the vertical support leg portion of each bridge-crane member and such as to permit said rotatable mounting sleeve and attached stand-off wall abutment struts to be rotatably moved back and forth in a horizontal plane so as to come into friction contact with the building support wall at a selected position and be locked in that selected position by means of the provided friction locks.
 10. The portable combination step ladder and bridge-crane structure described in claim 8 in which each of the horizontally positioned spaced-apart stand-off wall abutment struts are adapted for adjustable length of the wall engaging strut by providing each of said struts with a telescoPing extension member together with provision of a friction lock on each strut member adapted to lock the telescopic extension member into a selected position in order to provide improved stability to the ladder and bridge-crane assembly at a controlled spaced apart position from the building wall.
 11. The portable combination step ladder and bridge-crane structure described in claim 8 in which each of the horizontally positioned spaced-apart stand-off wall abutment struts are provided with swivelable adjustable friction secured foot members in order to prevent the bridge-crane structure from slipping laterally with respect to the abutting building while a load is being lifted to the roof of the building.
 12. The portable combination step ladder and bridge-crane device described in claim 8 together with a folding step to bridge the space between the top of the associated vertical support attachable-detachable step-ladder and roof of the building to be serviced, said folding step having A. a pair of parallel spaced apart step supporting arms of a length somewhat greater than the length of the stand-off wall abutment struts and somewhat shorter than the length of the horizontal portion of the inverted U shaped bridge-crane members, B. a transverse step platform mounted between said parallel step supporting arms at intermediate points near the midpoint in the length of each of said step supporting arms, and C. with said step platform support arms being connected to intermediate points on the outside vertical portion of the inverted U-shaped bridge-crane members by toggle hinges such as to permit the folding step platform to be rotated between a vertical folded out-of-the-way position generally parallel to the associated attachable-detachable step-ladder and vertical portion of the inverted U-shaped bridge-crane members - and alternately rotated upward to a horizontal position with one end of said hinged folding step and step supporting arms being supported on the upper wall sill of the building being serviced and the other ends of the hinged step supporting arms being supported by hinge connections from selected points on the outside vertical portion of inverted U-shaped bridge-crane members, and having a folding step draw line attached to the inside edge of the folding step to permit the operator to raise said folding step into a horizontal position while the operator is standing on the roof of the adjacent building.
 13. The portable combination step-ladder and bridge-crane structure described in claim 12 in which one end of the toggle hinges supporting the hinged folding step is fabricated in the form of a tubular shaped sliding-adjustable clamp with friction lock devices built into each of said clamp toggle hinges so that said folding step can be raised or lowered as necessary to permit the folding step platform to sit level with the upper wall sill of the building when the folding step is rotated up to its horizontal operative position.
 14. A portable bridge-crane cap structure designed to be supported at a distance above ground between an attachable-detachable support structure provided by the user as a first vertical support means and the wall and roof of a building as a second vertical support means together with a swivel mounted pulley-hoist means for lifting materials and equipment to the roof of a building where construction or repair work is to be done, or equipment such as an air compressor is to be installed, said bridge-crane cap structure comprising: A. a pair of spaced apart generally broad inverted U-shaped bridge-crane members
 15. The portable combination step ladder and bridge-crane device described in claim 14 together with a folding step to bridge the space between the top of the associated vertical support attachable-detachable step-ladder and roof of the building to be serviced, said folding step having A. a pair of parallel spaced apart step supporting arms of a length somewhat greater than the length of the stand-off wall abutment struts and somewhat shorter than the length of the horizontal portion of the inverted U-shaped bridge-crane members, B. a transverse step platform mounted between said parallel step supporting arms at intermediate points near the midpoint in the length of each of said step supporting arms, and C. with said step platform support arms being connected to intermediate points on the outside vertical portion of the inverted U-shaped bridge-crane members by toggle hinges such as to permit the folding step platform to be rotated between a vertical folded out-of-the-way position generally parallel to the associated attachable-detachable support structure and vertical portion of the inverted U-shaped bridge-crane members - and alternately rotated upward to a horizontal position with one end of said hinged folding step and step supporting arms being supported on the upper wall sill of the building being serviced and the other ends of the hinged step supporting arms being supported by hinge connections from selected points on the outside vertical portion of inverted U-shaped bridge-crane members, and having a folding step draw line attached to the inside edge of the folding step to permit the operator to raise said folding step into a horizontal position while the operator is standing on the roof of the adjacent building.
 16. The portable combination step-ladder and bridge-crane structure described in claim 14 in which one end of the toggle hinges supporting the hinged folding step is fabricated in the form of a tubular shaped sliding-adjustable clamp with friction lock devices built into each of said clamp toggle hinges so that said folding step can be raised or lowered as necessary to permit the folding step platform to sit level with the upper wall sill of the building when the folding step is rotated up to its horizontal operative position. 